The hyperbolic response is "look at what all the countries without weekly/daily mass shooting are doing and copy them"
In reality it'd need to be something culturally systemic, the removal of guns as a cultural touchstone over generations, with laws slowly applied to back up that effort.
Address the root causes of this kind of violence, quality of life, poverty, mental health in general, Provide mental health support and improve conditions so that less support is needed.
and that'd only be scratching the surface.
To address your specific response, banning guns outright probably would bring these numbers down and if these specific numbers going down was the ultimate (and only) goal then that would make sense, but in reality there would probably be significant issues cause by such a move.
Not to say it isn't viable, just that it's not clear cut.